1. Field of the Invention
This invention constitutes a means and method for the excision of tissue from within the lumen of a vessel in a human or animal by the use of an Endoluminal Tissue Excision Catheter (ETEC) system. Although much of the description herein concerns atherectomy of plaque from within an artery, this invention is more generally applicable to the excision of any tissue from any vessel of a living body.
2. Description of the Prior Art
There are numerous treatments to remove tissue from lumens within the vessels in a living body including surgical interventions such as endarterectomy and by-pass surgery using veins or artificial graft materials. Balloon angioplasty is becoming increasingly popular for the dilation of arterial stenoses without the excision of the plaque. More recently atherectomy, the excision from an artery of atheromatous plaque, has been successfully used to open arterial stenoses.
In UK Patent Application 2,044,103A by D.N. Ross dated Oct. 15, 1980 there is described a device for removing plaque within an artery by drawing together two cutting edges that are initially placed on either side of an arterial stenosis. There are numerous disadvantages of the Ross invention, namely: (1) two cutting edges are required which is more costly and complex as compared to one cutting edge, and two edges require very precise alignment in order to properly cut without tearing, (2) Ross does not teach a means to prevent dulling of the head's cutting edge 4 as it is pulled into the body 1, (3) no guide wire means is taught by Ross to guide the cutting head to and through the stenosis, (4) the entire distal portion is rigid for a considerable length; explicitly Ross lacks a long flexible tip thereby making it difficult for the catheter tip to pass through highly curved blood vessels, (5) Ross does not teach a means for injecting contrast media, (6) Ross does not teach a means for flushing out the excised tissue from the tissue collection chamber, and (7) Ross does not teach rotation or mechanical vibration of the cutting edge so as to enhance the cutting action.
U.S. Pat. No. 4,765,332, issued Aug. 23, 1988 to Robert E. and Tim A. Fischell, entitled "Pullback Atherectomy Catheter System," teaches a retrograde cutting catheter that can be advanced over a guide wire with a single cutting edge that can be rotated or mechanically vibrated, but does not teach a separate means to enclose the cut plaque in the plaque collection chamber after it has been cut or a means for injecting contrast media through the catheter's distal end, or several other novel and useful features of the invention described herein.